OK, the review of VS 'vGo' Auto 1000mAh is here.
As posted previously, this KR8 fat batt is a regulated 3.7v (3.69v on multimeter, btw) with sealed post. The
thread end has another
thread for cone (which cone is not known yet but some report KGO cone fits but regular VGO cone doesn't) and surprisingly fit iGo carto and iGo Crystal Vision. The other end has solid cap with small hole with LED at the end (see the picture), much like Echo stealth. In general, physically it's a hybrid between Echo body & iGo thread. The body length minus the thread is around 3.5" and with normal KR8 carto attached is less than 5".
The draw is good, less tight than the regular sealed KR8 but has the same, annoyingly - at least for some, short 5 seconds cut-off. Personally, I don't mind because with this size, remind me of my cigar day, I have the tendency to do some short puffs sequently so I never hit the cut-off. So if you are looking for a longer cut-off, you'll be dissapointed. Also like the new Echo stealth, if you close the LED hole, it will not work.
This battery fits and works nicely with iGo carto & clearo (see pictures). Somehow the draw is improved and vapor amount is as expected from echomizer style carto and vision style clearo. Echo carto/clearo also fit but it will leave the bigger thread exposed and for some it aesthetically not pretty.

At $19.99, it came with USB (4.2v/420mAh) and Wall charger (5v/500mAh). Charge time around 2-3 hours. Battery life varied but it supposed to last at least a day.
I like it and I think it probably the same build as the new Volt X2 without PT, varied mAh, different colors and longer cut-off. If it is then for Volt X2 owner can use iGo's stuffs to enjoy almost 3ml carto (the skirt will reduce juice amount) and vision style clearo.
So, if you don't mind 5 seconds cut-off, with that price (charger included) this is a good KR8 fat batt. Expansion is aesthetically limited to iGo's stuffs, but if you don't care you could use any KR8 compatible cartos on it. I never try it with LR cartos because I don't have any and personally, I don't really care about LR.
There you go. KR8 users, you have more choice now.